In 2013, the Dallas Cowboys fielded the worst defense in the National Football League. In the offseason, they lost defensive end DeMarcus Ware and defensive tackle Jason Hatcher to free agency. Linebacker Sean Lee was lost for the season to a torn ACL in OTAs.

Well, they say desperate times call for desperate measures, and it appears the Cowboys are putting that axiom to the test.

As Adam Schefter of ESPN reported, the Cowboys have swapped draft picks with the Baltimore Ravens in a deal that brings linebacker (and former top-10 pick) Rolando McClain to Big D:

I gotta follow my heart. It ain't football. If football made me complete I would play. But whenever I think of it my heart pulls me away from whatever reason. ... This means I'm done.

Now, not even three months later, Mike Garafolo of Fox Sports passes along word from McClain's agent that McClain has changed his mind again.

It's a microcosm for McClain's career, which has had more twists and turns than an episode of Scandal.

Once upon a time, McClain was going to be the NFL's next great linebacker. Bleacher Report NFL National Lead Writer Matt Miller, writing at the time for New Era Scouting, praised the eighth overall pick in the 2010 NFL draft:

McClain is the most sure-thing as a middle linebacker prospect in the draft since Patrick Willis. He’s a prototypical combination of size, athleticism and intelligence. If McClain somehow turns out to be a bust, it will be a shock.

Well, fire up Old Sparky, because McClain was just that.

Rolando McClain Career Stats

Year

Tackles

Sacks

INT

FF

PFF Rank*

2010

85

0.5

1

0

14

2011

99

5.0

0

0

23

2012

62

1.0

0

1

11

* Per Pro Football Focus

In his three years in Oakland, McClain's play got steadily worse from one season to the next. By his third season in 2012, McClain's work ethic was questioned, he was openly feuding with the coaching staff and the Raiders were pulling McClain from the field on passing downs.

The Raiders granted his wish and released McClain the following April, but after signing with the Ravens, McClain retired before going through the same motions again a few months ago.

Frankly, at this point, calling it even money that McClain plays a single regular-season snap for the Cowboys is probably being optimistic.

After all, he hasn't put on pads, much less played in over a year, so conditioning is an issue. So is his dedication, given that McClain has retired twice as many times before the age of 25 as most people do during their entire lives.

Then there's the matter of the three arrests since December of 2011:

From 2011 .. Newest Dallas Cowboy Rolando McClain was arrested for holding a gun to a man's head and firing a shot pic.twitter.com/7Z4y8HO6n2

Of course, flipping Durant inside raises problems, too. The Cowboys already have plenty of issues in the front seven without adding to them by making the strong side of their defensive formation weaker than it already was.

How many games will Rolando McClain play for the Cowboys in 2014?

01-45-910 or moreSubmit Votevote to see results

How many games will Rolando McClain play for the Cowboys in 2014?

0

20.6%

1-4

17.9%

5-9

18.9%

10 or more

42.6%

Total votes: 5,699

In that regard, McClain just might be of assistance. For all his deficiencies, McClain was a solid run-stuffer in the NFL. According to Pro Football Focus (subscription required), McClain ranked in the top 10 among inside linebackers in run defense, run stop percentage and tackling efficiency during his last season in 2012.

If the Cowboys can get a viable two-down thumper who can help a run defense that allowed over 125 yards a game on the ground last year, this deal will have been more than worth it.

Is it possible McClain could do more? Sure. After all, he's still only 24 years old, and physical talent was never the problem.

Of course, it's just as likely (if not more so) that McClain won't do anything, and for that reason the best course of action right now is to take things slowly and temper expectations.

Because before we know what Rolando McClain brings to the table in Dallas, we have to make sure he shows up for dinner.

Gary Davenport is an NFL Analyst at Bleacher Report and a member of the Fantasy Sports Writers Association and the Pro Football Writers of America. You can follow Gary on Twitter @IDPManor.